Sjogren's syndrome is an immunological disorder characterized by dry eyes and dry mouth, which includes diminished or absent secretion of glandular tissue. SNI-2011, a quinuclidine derivative of acetylcholine, is a muscarinic agonist associated with improved glandular ability to increase salivation and lacrimation. This study will compare the efficacy of two doses of SNI-2011 (15 mg and 30 mg tid) with placebo on the patients' subjective global evaluation of dryness (mouth, eyes, and overall).